Until fairly recently, packaging materials, such as loose fill, consisted mainly of polystyrene also known as "Styrofoam". However, the use of such non-biodegradable plastic materials poses a serious threat to the environment. Therefore, manufacturers have recently begun to make packaging materials from expanded starch products. For example, U.S. Pat. Nos. 4,863,655; 5,035,930 and 5,043,196 disclose compositions and methods for making an expanded starch material having an at least 45% by weight amylose content. The starches in these compositions have been modified by etherification with alkylene oxides. One of these compositions comprising starch which has been hydroxypropylated with propylene oxide is made by National Starch, Bridgewater, N.J., and sold on the market as ECO-FOAM.TM.. It is, however, quite expensive and the other existing products are either also expensive or too brittle or too heavy to be truly practical for packaging material.
Therefore, an inexpensive, biodegradable, highly resilient packaging material would be extremely desirable in commerce.